I'm looking on ebay for a D-104 microphone to use with my Heath Marauder
transmitter, and I need to make sure I get the right one.

There seems to be differences between models... some are amplified, some
are not; some are high impedance, and some are low.

The sellers for these mics are highly unlikely to know anything worth
knowing about them it seems... so, which one do I need for my Marauder and
how do I make sure I'm getting the right one?

Thanks...